Yes i do! here it is. This is my background research findings and what is also believe to be true.
New research looks at the involvement of SSRI’s in the treatment of depression and has discovered they appear to increase neurogenesis (source).Neurogenesis is the birth of new cells in the brain, and throughout life new neurons will grow in the area of the brain called the hippocampus (responsible for memory).Research has shown that after several weeks of taking anti-depressants there is an increase of neurogenesis (The Guardian).This helps to explain why anti-depressants such as SSRI’s take one to four weeks to alleviate symptoms, suggesting it is neurogenesis that alleviates depression symptoms and not the inhibited reuptake of serotonin. This also suggests that the hippocampus is affected by depression by either cause or effect.
Reactive depression (sane.org.uk) is often caused by a specific stressful situation or an accumulation of a number of stressful situations. The body releases glucocorticoids in response to stressful experiences which are beneficial for homeostatic functions. Glucocorticoids act on the hippocampus, amygdala, and frontal lobes. Along with adrenaline these enhance the formation of flashbulb memories of events associated with strong emotions both positive and negative (Brown and Kulik, 1977). Elevated glucocorticoid levels result is damage to the hippocampus (Sapolsky et al, 1990). Damage to the Hippocampus results in decrease of serotonin 5HT receptor binding to the hippocampus and also a decrease in BDNF (Brain derived neurotrophic factor) which are proteins produced in the brain that promote neuron growth and stops neurons dying. BDNF may cause hippocampus atrophy (brain damage that impacts memory and spatial navigation) or cell death (Smith, 1995). Studies studying severe depression used MRI technology to image the hippocampus (Sapolsky, 2000) found that all subject reported hippocampus atrophy which did not resolve over time and appeared to be irreverable. If depression if caused by damage to the hippocampus due to stress, then the results explain why depression has a high lifetime prevalence rate; 9.7% for depression and anxiety and 2.6% depression (The Health & Social Care Information Centre, 2009)
Alternative therapies are also available for the treatment of depression. Meditation has now become popular in the west and psychologists are studying its effectiveness on treating depression. In a book titled; ‘Mindfulness’ (by Mark Williams, a professor in clinical psychology at the university of oxford, and Dr Danny Penman, PHD biochemistry) the use of meditation in treatment of depression is explored in the style of a self help book for the reader. Research in the book notes that people who meditate see a decrease in depression, anxiety and irritability (G.T. Hopkins et al, ‘using self report assessment methods to explore facets of mindfulness’ 2006) and note memory improvements (Jha et al ‘mindfulness training modifies subsystems of attention’ 2007). Research into the benefits of meditation is becoming a growing subfield in neurological science. Britta K. Holzel et al posted a research article titled; ‘Mindfulness practice leads to increases in regional brain gray matter density’. Research in the report revealed that those who meditated for about 30 minutes a day for eight weeks had measurable changes in gray-matter density in parts of the brain associated with memory, sense of self, empathy and reduced stress.
Meditation is not the only activity that triggers neurogenesis; research has been conducted into how exercise can also bring about neurogenesis in humans. Pereira et al. (2007) conducted research on the effects of aerobic exercise on the brain and concluded; ‘Research in humans and animals has shown that exercise improves mood and cognition. Physical activity also causes a robust increase in neurogenesis in the dentate gyrus of the hippocampus, a brain area important for learning and memory’. (Neurogenesis and Exercise: Past and Future Directions, Henriette van Praag 16 January 2008).
Dr Steve Llardi, author of ‘The depression cure’, suggests that depression is an illness caused by modern day lifestyle. In his book he reports that modern day life of commuting to work, working in an office environment eating junk food goes against our DNA. He concluded that the result is; ‘We feel perpetually stressed. And the more we learn about depression neurologically, the more we learn that it represents the brain's runaway stress response’. His conclusions are supported by research previously discussed and by further research into depression rates amongst people who live in less industrialised societies such as The Kaluli people, Papua New Guinea, in which there was a 0% depression rate (Edward Schieffelin, 1976).
According to the office of national statistics, doctors in England issued 39.1 million prescriptions for various anti-depressants in 1991, compared to 9 million in 1991 (The Telegraph). Statistically 10% of adults are clinically depressed and only one quarter of these adults are receiving medication and/or counselling. An astonishing statistic is that people born after 1945 are 10% more likely to suffer from clinical depression at some point in their lives (taken from;
Depression - Understand it, Treat it, Beat it). A survey conducted by KitKat Kubes for National stress awareness day (5th November) reported that 70% of people were stressed (‘we can all do something about stress’, HR Zone). The correlation between depression and the brains stress response is interesting and has an excellent amount of research to suggest new explanations in possible alternative causes of depression.
